1. Field of the Invention
The present invention generally relates to the field of semiconductors and semiconductor packaging. In particular, the present invention relates to an improved integrated circuit (IC) package and a method of assembling the same.
2. Discussion of Related Art
Semiconductors are materials that have characteristics of insulators and conductors. In today's technology, semiconductor materials have become extremely important as the basis for transistors, diodes, and other solid-state devices. Semiconductors are usually made from germanium or silicon, but selenium and copper oxide, as well as other materials are also used. When properly made, semiconductors will conduct electricity in one direction better than they will in the other direction.
Semiconductor devices and ICs are made up of components, such as transistors and diodes, and elements such as resistors and capacitors, linked together by conductive connections to form one or more functional circuits. Interconnects on an IC chip serve the same function as the wiring in a conventional circuit.
Once the components of an IC package have been assembled, the package is typically sealed by plastic encapsulant in order to improve the strength of the package and to provide necessary protection to components within.
FIGS. 1A through 1D illustrate a wafer-level chip scale package (WLCSP) according to the prior art. According to the prior art, pillar bumped wafers are encapsulated as shown in FIG. 1A, such that the encapsulation material 15 covers the upper ends of the pillar bumps 16. After encapsulation, the molded wafer is polished, as shown in FIG. 1B to remove an upper layer of encapsulation material. Solder 17a, as shown in FIG. 1C is then printed on the upper ends of the pillar bumps 16 and is reflowed to form solder bumps 17b. 